Bentley started his career with Arsenal in the Premier League, and despite being earmarked as one for the future, saw his playing opportunities limited by a strong senior squad. He spent two seasons on loan with Norwich City and Blackburn Rovers, and sealed a permanent transfer to Rovers in January 2006. Bentley produced strong performances for his new club, and soon featured regularly for the England under-21 team. He made his senior international debut against Israel in September 2007. In July 2008, Bentley joined Tottenham Hotspur. He spent time on loan with Birmingham City, West Ham United, FC Rostov and a brief return to Blackburn before being released by Tottenham in 2013. After not playing for more than a year, Bentley retired from football in 2014, citing his loss of passion for the sport.

Bentley spent the whole of the next league season on loan to Norwich City, playing 26 league games and scoring two goals, against Newcastle and Southampton.[8] His season at Carrow Road was interrupted by an injury sustained in January.[citation needed] He returned to the side in April 2005, coming off the bench against Manchester United and playing a key role in Norwich's 2–0 win.[9] Despite a late run of form, the Canaries were relegated from the Premier League on the last day of the season.[citation needed] Bentley returned to Arsenal in the summer of 2005, but submitted a transfer request, citing his desire for first team football.[5] In subsequent interviews, he also revealed that he was having "personal problems" at that point in his career and had lost his enjoyment for football—problems which he overcame later in his Blackburn Rovers career.[10] He admitted to gambling addiction in the early stages of his career, reaching a peak of placing 100 bets a day. He got over his problems in 2005.[11]

In January 2006, Blackburn signed Bentley on a permanent basis from Arsenal.[13] In his first match after permanently signing for Blackburn, he scored his first senior hat-trick in a 4–3 victory against Manchester United.[13] Bentley went on to feature regularly for Blackburn in the 2005–06 season, and helped the club finish sixth in league standings and qualify for the 2006–07 UEFA Cup.[8][14]

The 2006–07 season saw Bentley become more of a regular goalscorer for Rovers, including some stunning strikes in the Premier League.[15][16] In Europe, a 25-yard volley against Salzburg in the UEFA Cup helped secure Rovers' passage into the group stage,[17] where he also scored a last minute winner against Wisła Kraków.[18] Bentley's club performances attracted much transfer speculation.[citation needed] However, on 27 February 2007, despite being linked to a move to Manchester United, he agreed to a new contract that would keep him with Blackburn until 2011.[19][20] Commenting on the new deal, Rovers manager Mark Hughes described Bentley as "a great talent with a big future" while Chairman John Williams added that he "is widely regarded as one of the best young footballers in the country."[20] Bentley ended the season with seven goals and 13 assists for Blackburn, the latter statistic also highlighting his creative importance to the team.[8] The young midfielder was later voted by Rovers fans as the club's Player of the Year.[21]

Bentley recorded similar statistics in the following season, scoring eight goals and providing 13 assists.[8] Blackburn finished seventh in the Premier League, but did not qualify for European competition.[citation needed] Bentley's consistent performances for his club, however, ensured that he played in a series of post-season friendlies for England.[citation needed] But that was to be the Englishman's final season with the Lancashire club.[citation needed] Not long after the departure of manager Mark Hughes to Manchester City, Bentley reiterated his desire to join a bigger club, and Blackburn placed a valuation of the player at around £18 million.[citation needed]

On 31 July 2008, Tottenham Hotspur announced their signing of Bentley, on a six-year contract, for a £15 million fee, with an additional £2 million conditional on future performance.[22] Reports suggested that £7 million of this fee was payable to Bentley's former employers, Arsenal.[22][23] Bentley made his competitive debut on 16 August 2008 away at Middlesbrough where Spurs lost 2–1.[24] He scored his first competitive goal for Spurs in the 2008–09 UEFA Cup first round tie against Wisła Kraków on 18 September 2008. He then scored his first league goal for Tottenham against his old club Arsenal with a 43-yard dipping volley in a 4–4 draw on 29 October 2008.[25] This led the British mathematician Tony Mann to ask Marcus du Sautoy to name a symmetry group in honour of David Bentley; the group is labelled Set [C[1], C[2], C[3], C[4]]=[40, 13, 4, 4], with the final two digits corresponding to the result of the match.[26] Bentley's form would suffer at Tottenham, however, and after falling down the pecking order for both club and country, it was reported on 17 June 2009 that he was in talks to move to Aston Villa.[27] Subsequently, it was revealed by Bentley and Aston Villa that this was untrue.[28]

On 31 August 2011, Bentley signed a season-long loan deal with Championship side West Ham United.[33] He made his debut on 10 September 2011 in a 4–3 home win against Portsmouth coming on in the 63rd minute for Julien Faubert.[34] In October 2011, he was ruled out for six months following a knee operation and returned to Tottenham for treatment, after playing five matches for West Ham.[35] In February 2012, Bentley was named in Tottenham's 25-man squad for the second half of the 2011–12 season despite his injury.[36]

Despite featuring prominently in Tottenham's pre-season under new manager André Villas-Boas, on 7 September 2012, Bentley went out on loan to Russian side FC Rostov.[37] Bentley became the first Englishman to play in the Russian Premier League when he made his debut for the club on 15 September, playing the full 90 minutes in a 1–0 victory over Dynamo Moscow.[38][39] He went on to start all four subsequent league games for Rostov before picking up an ankle injury in the 0–0 draw with Lokomotiv Moscow on 21 October.[citation needed] Bentley made seven appearances for Rostov without scoring.[40]

In January 2013 Bentley's former manager at Tottenham, Harry Redknapp, attempted to sign him on loan for Queens Park Rangers as a potential supplier of crosses for Peter Crouch.[citation needed] However, the move did not take place because Crouch did not sign for QPR and Bentley's weekly wage of £50,000 was deemed too high.[41] On 15 February, Bentley returned to former club Blackburn Rovers on a 93-day loan.[42] He made his second Blackburn début the next day, coming on as substitute in a fifth round FA Cup away win at Arsenal.[43]

On 13 June 2014, Bentley announced his retirement from professional football at the age of 29, having been without a club for over a year. He stated in an interview that he had fallen out of love with football, calling the modern game "robotic" due to the influence of social media and money, as well as "predictable and a bit too calculated". He said that he wished to spend time with his three children.[46][47] By October 2014, Bentley was a co-owner of a restaurant in Marbella, Spain, where he and his family had moved to.[48] Bentley has also invested in beach clubs and in a restaurant in Woodford Green, London with Raheem Sterling and Alex Oxlade-Chamberlain.[49][50]

Most commonly Bentley played as a right winger, but he could also play as a central midfielder or a second striker. When he was at Arsenal, Bentley was slated to play in the second striker role, but[5] after joining Blackburn he found himself deployed more frequently on the right side of midfield due to his ability to cross the ball.[citation needed] He was a set-piece specialist and regularly took charge of corner and free-kick duties for his team.[citation needed] He was known for his technique, composure and creativity on the ball and was often talked about as a should-be central midfielder, but his ability to deliver from wide positions meant he was often used as a winger, despite lacking the pace of some of his Premier League contemporaries.[citation needed]